def greet_user(first_name,last_name):
    #显示简单的问候语
    full_name = f"{first_name} {last_name}"
    return full_name

while True:
    print("\nPlease tell me your name")
    print("(enter 'q' finish this program)")
    f_name =input("Please tell me your first_name:")
    if f_name=='q':
        break
    l_name =input("Please tell me your last_name:")
    if l_name=='q':
        break
    full_name =greet_user(f_name,l_name)
    print(f"Hello,{full_name}")